1. Field of the Invention
This invention generally relates to the field of telemedicine systems, and more particularly to a patient monitoring station comprised of a plurality of medical devices in communication with a single control unit.
2. Background Information
Traditional telemedicine systems are manufactured in a rigid manner with set numbers of medical devices packaged into a single product. Each medical device is connected to a computer with its own interface. This can be accomplished through the use of the standard serial ports on the computer and/or the addition of interface cards to support the devices. Each one of these ports and/or cards uses a single interrupt for each connected device.
Interrupts are commonly used to initiate real-time communication between a computer and a connected peripheral device. When a peripheral device has data to transmit to the computer, the device will generate a hardware interrupt to notify the computer of its request. An interrupt handler on the computer will detect the interrupt and dispatch an interrupt service routine (ISR) to process the interrupt. In general, interrupt requests are high priority events that result in suspension of the current running process on the computer to allow the ISR to run. In the event that multiple peripherals send interrupt request signals to the computer, a priority scheme can be implemented to determine the order in which the interrupts will be processed.
As discussed in the foregoing, current telemedicine systems use multiple interrupts and/or multiple cards and interfaces for multiple connected medical devices. Several problems are associated with this approach of using an interrupt for each medical device attached to a computer in a telemedicine system. Obviously, the total system cost and complexity is increased simply by using multiple cards. Additionally, the use of multiple cards reduces the number of available card slots in a computer, thereby limiting the number of additional cards and peripherals that can be attached to the computer. The addition of a new medical device often requires the installation of a new card, which can be time consuming. Finally, the number of medical devices that can be attached to a computer in a telemedicine system is limited to the number of available interrupts.